Internal olefin sulfonate composition

ABSTRACT

Provided are an internal olefin sulfonate composition which is capable of sufficiently enhancing foamability, foam dissipation property free from a slimy feeling during rinsing, and a feel after cleansing and subsequent drying, and a cleansing composition containing the same. 
     The internal olefin sulfonate composition comprises (A) an internal olefin sulfonate having 16 carbon atoms and (B) an internal olefin sulfonate having 12 carbon atoms, in which a content mass ratio of the component (A) to the component (B), (A/B), is from 10/90 to 90/10.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. patent application Ser. No.14/764,304 filed on Jul. 29, 2015, which was filed as the National Phaseof PCT International Application No. PCT/JP2014/052257 filed on Jan. 31,2014, which claims the benefit of priority to Japanese Application No.2013-018594 filed on Feb. 1, 2013, all of which are hereby expresslyincorporated by reference into the present application.

FIELD OF THE INVENTION

The present invention relates to an internal olefin sulfonatecomposition useful as a base for a cleansing agent, and to a cleansingcomposition containing the internal olefin sulfonate composition.

BACKGROUND OF THE INVENTION

Anionic surfactant, particularly, alkyl sulfate and alkylpolyoxyalkylene sulfate, is excellent in detergency and foaming power,and thus are widely used as cleansing ingredients for domestic orindustrial use. An olefin sulfonate, particularly, an internal olefinsulfonate obtained with an internal olefin having a double bond insidean olefin chain, not at its end, as a raw material, has been reported asone of the anionic surfactant.

Such an internal olefin sulfonate is generally obtained by sulfonatingan internal olefin through reactions with a gaseous sulfurtrioxide-containing gas, followed by neutralization and then hydrolysisof the resulting sulfonic acid. For example, Patent Document 1 disclosesan improved production method thereof.

The internal olefin sulfonate thus obtained is known to have goodbiodegradability or the like, but is still insufficient in a basicperformance as cleansing agent including foamability and foaming speed,compared with general-purpose surfactant such as alkyl polyoxyalkylenesulfuric acid ester salt. Thus, further improvement in such basicperformance has been desired. As more people have concerned thewater-saving or consumers' preferences have been diversified in recentyears, the additional value of foam dissipation property free from aslimy feeling and a good feel after drying in addition to goodfoamability has also been required for use as major activator in laundrydetergents, dishwashing detergents, shampoos or the like. Specifically,it has been desired to develop a surfactant composition having excellentfoam dissipation property free from a slimy feeling during rinsing whilebringing about a good feel without perceivable residue from thecleansing agent after cleansing and subsequent drying. Such anadditional value is useful for, for example, body cleansers and hairshampoos. As more people have a habit to wash their hair or bodieswithin a limited time before leaving the house after awakening, orbefore going to bed, they are unsatisfied with a long time required forrinsing or an unpleasant feel after cleansing and subsequent drying.Particularly, young people, who have active metabolism and secrete alarge amount of sebum, etc., tend to strongly desire a refreshed feelfree from a slimy feeling on their scalps or bodies. If a surfactantcomposition which exerts foam dissipation property free from a slimyfeeling and a good feel after drying can be formulated, this compositionnot only permits rinsing in a short time but can bring about a refreshedfeel after drying, leading to the realization of water-saving.

Then, Patent Document 2 discloses a specific internal olefin sulfonicacid which is intended to impart the solubilizing ability, penetratingability, and interfacial tension reducing ability as a cleansingcomponent. It discloses that when it is used as, for example, a shampoo,it lathers well without friction, and achieves an improved feel. PatentDocument 3 also describes a specific internal olefin sulfonate for thepurposes of improving detergency, and discloses examples of applicationto shampoos, liquid soaps, and the like. Meanwhile, Patent Document 4describes a promoter for recovering an oil using a surfactant containinga plurality of internal olefin sulfonates differing in the number ofcarbon atoms.

[Patent Document 1] JP-A-59-222466

[Patent Document 2] JP-A-2003-81935

[Patent Document 3] U.S. Pat. No. 5,078,916

[Patent Document 4] WO-A 2010/129051

SUMMARY OF THE INVENTION

The present invention relates to an internal olefin sulfonatecomposition comprising (A) an internal olefin sulfonate having 16 carbonatoms and (B) an internal olefin sulfonate having 12 carbon atoms,wherein a content mass ratio of the component (A) to the component (B),(A/B), is from 10/90 to 90/10.

The present invention also relates to a cleansing composition comprising(A) an internal olefin sulfonate having 16 carbon atoms and (B) aninternal olefin sulfonate having 12 carbon atoms, wherein a content massratio of the component (A) to the component (B), (A/B), is from 10/90 to90/10.

DETAILED DESCRIPTION OF THE INVENTION

Further improvement is still required for any of the compositionsdescribed in the above-mentioned documents to exert good foamabilitytogether with foam dissipation property free from a slimy feeling duringrinsing and a feel after cleansing and subsequent drying at high levelsas a cleansing agent which is applied to hair, the skin, or the like.

Therefore, the present invention relates to an internal olefin sulfonatecomposition which is capable of sufficiently enhancing foamability, foamdissipation property free from a slimy feeling during rinsing, and afeel after cleansing and subsequent drying, and a cleansing compositioncontaining the internal olefin sulfonate composition.

The present inventors studied a length of an aliphatic chain in aninternal olefin sulfonate, a ratio thereof and other various conditions,and consequently found that an internal olefin sulfonate compositionwhich satisfies good foamability and can also exert excellent foamdissipation property free from a slimy feeling during rinsing whilebringing about a good feel without perceivable residues from thecleansing agent after cleansing and subsequent drying can be obtained bysetting the ratio between an internal olefin sulfonate having 16 carbonatoms and an internal olefin sulfonate having 12 carbon atoms to apredetermined range. On the basis of these findings, the presentinvention has been completed.

According to the present invention, it can provide an internal olefinsulfonate composition which satisfies good foamability and also exertsgood foam dissipation property free from a slimy feeling during rinsingwhile sufficiently bringing about a good feel without perceivableresidues from the cleansing agent after cleansing and subsequent toweldrying, for example, and a cleansing composition containing the internalolefin sulfonate composition.

Hereinbelow, the present invention will be described in detail.

<Internal Olefin Sulfonate Composition>

The internal olefin sulfonate composition of the present inventionincludes (A) an internal olefin sulfonate having 16 carbon atoms and (B)an internal olefin sulfonate having 12 carbon atoms, in which a contentmass ratio of the component (A) to the component (B), (A/B), is from10/90 to 90/10.

In the present invention, an internal olefin sulfonate is a sulfonateobtained by sulfonating an internal olefin (an olefin having a doublebond inside the olefin chain) as the raw material, followed byneutralization and then hydrolysis, as described above. That is,sulfonation of an internal olefin quantitatively produces β-sultone,some of which are converted into γ-sultone and olefin sulfonic acid,which are further converted into hydroxyalkane sulfonate and olefinsulfonate in the process of neutralization and hydrolysis (for example,J. Am. Oil Chem. Soc. 69, 39 (1992)). It should be noted that the aboveinternal olefin may also has a broad meaning including a trace amount ofso-called α-olefin, in which a double bond is present at the C-1position of the carbon chain. Here, the hydroxyl group of thehydroxyalkane sulfonate thus obtained is present inside the alkanechain, and the double bond of the olefin sulfonate thus obtained ispresent inside the olefin chain. Also, the product thus obtained ismainly a mixture of the aforementioned substances, some of which mayinclude a trace amount of hydroxyalkane sulfonate having a hydroxylgroup at the end of the carbon chain, or olefin sulfonate having adouble bond at the end of the carbon chain. In the presentspecification, each of these products and a mixture thereof arecollectively referred to as internal olefin sulfonate. Hydroxyalkanesulfonate is referred to as the hydroxy form of an internal olefinsulfonate (hereinbelow, may also be referred to as HAS), and olefinsulfonate is referred to as the olefin form of an internal olefinsulfonate (hereinbelow, may also be referred to as IOS).

A content mass ratio of the component (A) to the component (B), (A/B),in the internal olefin sulfonate composition of the present invention isfrom 10/90 to 90/10 from the viewpoint of foamability, foaming speed,foam dissipation property free from a slimy feeling during rinsing, anda feel after cleansing and subsequent drying, and is preferably from10/90 to 50/50, more preferably from 10/90 to 25/75, and even morepreferably from 10/90 to 15/85, from the viewpoint of foam dissipationproperty free from a slimy feeling during rinsing and a feel aftercleansing and subsequent drying. Also, the content mass ratio (A/B) ispreferably from 25/75 to 75/25, more preferably from 40/60 to 75/25, andeven more preferably from 40/60 to 60/40, from the viewpoint offoamability and foaming speed upon application to hair.

The content mass ratio of the component (A) to the component (B), (A/B),in the internal olefin sulfonate composition is a numerical valuemeasured by a high-performance liquid chromatograph-mass spectrometer(hereinbelow, abbreviated as HPLC-MS). Specifically, an internal olefinsulfonate having 16 carbon atoms and an internal olefin sulfonate having12 carbon atoms are separated by HPLC, each of which then is identifiedby analysis with MS. From the HPLC-MS peak area thereof, the contentmass ratio of the component (A) to the component (B), (A/B), in theinternal olefin sulfonate composition is obtained.

The total content of the component (A) and the component (B) in theinternal olefin sulfonate composition of the present invention ispreferably 50% by mass or more, more preferably 70% by mass or more,more preferably 80% by mass or more, more preferably 90% by mass ormore, more preferably 95% by mass or more, more preferably 96.5% by massor more, and even more preferably 97% by mass or more, from theviewpoint of foamability, foaming speed, foam dissipation property freefrom a slimy feeling during rinsing, and a feel after cleansing andsubsequent drying. The upper limit of the total content of the component(A) and the component (B) is preferably 100% by mass.

As is apparent from the aforementioned production method, the sulfonategroup in the internal olefin sulfonate of the present invention ispresent inside the olefin chain or alkane chain. In the presentinvention, it is preferable that the content of an internal olefinsulfonate in which the sulfonate group is present at the C-2 position ofthe olefin chain or alkane chain is low, while the content of aninternal olefin sulfonate in which the sulfonate group is presentfurther inside is high, from the viewpoint of foamability, foamingspeed, foam dissipation property free from a slimy feeling duringrinsing, and a feel after cleansing and subsequent drying. It is morepreferable that the content of an internal olefin sulfonate in which thesulfonate group is present at the C-2 position of the olefin chain oralkane chain is low, with respect to both of the above internal olefinsulfonates having 16 carbon atoms and 12 carbon atoms.

The content of the internal olefin sulfonate in which a sulfonate groupis present at a C-2 position in the internal olefin sulfonate (component(A) and component (B)) having 16 and 12 carbon atoms of the presentinvention is, in the total content of the component (A) and thecomponent (B), preferably 25% by mass or less, more preferably 22% bymass or less, more preferably less than 20% by mass, and even morepreferably less than 18% by mass, from the viewpoint of foamability,foaming speed, foam dissipation property free from a slimy feelingduring rinsing, and a feel after cleansing and subsequent drying. Thecontent of the internal olefin sulfonate in which a sulfonate group ispresent at a C-2 position in the component (A) and the component (B) is,in the total content of the component (A) and the component (B),preferably 5% by mass or more, more preferably 7% by mass or more, andeven more preferably 10% by mass or more, from the viewpoint offoamability, foaming speed, foam dissipation property free from a slimyfeeling during rinsing, and a feel after cleansing and subsequentdrying, cost, and productivity. Considering these viewpoints together,the content of the internal olefin sulfonate in which a sulfonate groupis present at a C-2 position in the component (A) and the component (B)is, in the total content of the component (A) and the component (B),preferably 5% by mass or more and 25% by mass or less, more preferably7% by mass or more and 22% by mass or less, more preferably 7% by massor more and less than 20% by mass, more preferably 7% by mass or moreand less than 18% by mass, and even more preferably 10% by mass or moreand less than 18% by mass.

The content of the internal olefin sulfonate in which a sulfonate groupis present at a C-2 position in the component (A) and the component (B)is, in the total content of the component (A) and the component (B),preferably 22% by mass or less and more preferably less than 20% bymass, and preferably 12% by mass or more, more preferably 14% by mass ormore, more preferably 17% by mass or more, and even more preferably 19%by mass or more, from the viewpoint of foam dissipation property freefrom a slimy feeling during rinsing and a feel after cleansing andsubsequent drying. Also, the content of the internal olefin sulfonate inwhich a sulfonate group is present at a C-2 position in the component(A) and the component (B) is, in the total content of the component (A)and the component (B), preferably 12% by mass or more and 22% by mass orless, more preferably 14% by mass or more and 22% by mass or less, morepreferably 17% by mass or more and less than 20% by mass, and even morepreferably 19% by mass or more and less than 20% by mass, from a similarviewpoint.

The content of the internal olefin sulfonate in which a sulfonate groupis present at a C-2 position in the component (A) and the component (B)is, in the total content of the component (A) and the component (B),preferably less than 20% by mass, more preferably 19% by mass or less,and even more preferably 17% by mass or less, and preferably 12% by massor more and more preferably 14% by mass or more, from the viewpoint offoamability and foaming speed during hair cleansing. Also, the contentof the internal olefin sulfonate in which a sulfonate group is presentat a C-2 position in the component (A) and the component (B) is, in thetotal content of the component (A) and the component (B), preferably 12%by mass or more and less than 22% by mass, more preferably 14% by massor more and 19% by mass or less, and even more preferably 14% by mass ormore and 17% by mass or less, from a similar viewpoint.

The content of the internal olefin sulfonate in which a sulfonate groupis present at a C-2 position in the component (A) and the component (B)is, in the total content of the component (A) and the component (B),preferably 22% by mass or less and more preferably 19% by mass or less,and preferably 12% by mass or more, more preferably 14% by mass or more,and even more preferably 17% by mass or more, from the viewpoint offoaming speed during skin cleansing. Also, the content of the internalolefin sulfonate in which a sulfonate group is present at a C-2 positionin the component (A) and the component (B) is, in the total content ofthe component (A) and the component (B), preferably 12% by mass or moreand 22% by mass or less, more preferably 14% by mass or more and 19% bymass or less, and even more preferably 17% by mass or more and 19% bymass or less, from a similar viewpoint.

A content of the α-olefin sulfonate in which the sulfonate group ispositioned at the C-1 position of an olefin chain or an alkane chain is,in the total content of the component (A) and the component (B),preferably less than 2.8% by mass and more preferably 2.0% by mass orless, from the viewpoint of foam dissipation property free from a slimyfeeling during rinsing and a feel after cleansing and subsequent drying.The content of the α-olefin sulfonate in which the sulfonate group ispositioned at the C-1 position of an olefin chain or an alkane chain is,in the total content of the component (A) and the component (B),preferably 0.01% by mass or more, more preferably 0.1% by mass or more,and even more preferably 0.3% by mass or more, from the viewpoint ofcost and productivity. Considering these viewpoints together, thecontent of the α-olefin sulfonate in which the sulfonate group ispositioned at the C-1 position of an olefin chain or an alkane chain is,in the total content of the component (A) and the component (B),preferably 0.01% by mass or more and less than 2.8% by mass, morepreferably 0.1% by mass or more and less than 2.8% by mass, morepreferably 0.3% by mass or more and less than 2.8% by mass, and evenmore preferably 0.3% by mass or more and 2.0% by mass or less.

It should be noted that the content of the internal olefin sulfonate inwhich the sulfonate group is present at the C-2 position in the internalolefin sulfonate having 16 and 12 carbon atoms may be measured by amethod such as nuclear magnetic resonance spectroscopy. Morespecifically, it is a numerical value measured by a method using gaschromatography described later in Example.

A content mass ratio of the hydroxy form to the olefin form, (hydroxyform/olefin form), in the internal olefin sulfonate having 16 and 12carbon atoms is preferably from 50/50 to 100/0, more preferably from60/40 to 100/0, more preferably from 70/30 to 100/0, more preferablyfrom 75/25 to 100/0, and even more preferably from 75/25 to 95/5, fromthe viewpoint of foam dissipation property free from a slimy feelingduring rinsing and a feel after cleansing and subsequent drying.

The content mass ratio of the hydroxy form and the olefin form in theinternal olefin sulfonate having 16 and 12 carbon atoms of the presentinvention may be measured by the method described later in Examples.

A content of an internal olefin sulfonate having 18 or more carbon atomsin the internal olefin sulfonate composition of the present invention ispreferably 5% by mass or less, more preferably 3% by mass or less, morepreferably 2% by mass or less, and even more preferably 1% by mass orless, from the viewpoint of foam dissipation property free from a slimyfeeling during rinsing and a feel after cleansing and subsequent drying.The lower limit of the content of the internal olefin sulfonate having18 or more carbon atoms is preferably 0% by mass, that is, it ispreferable that the internal olefin sulfonate composition of the presentinvention does not contain the internal olefin sulfonate having 18 ormore carbon atoms unless this internal olefin sulfonate is inevitablymixed therein.

Also, for the internal olefin sulfonate having 18 or more carbon atoms,it is also preferable to have a low content of the internal olefinsulfonate in which the sulfonate group is positioned at the C-2 positionof an olefin chain or an alkane chain and a high content of the internalolefin sulfonate in which the sulfonate group is positioned moreinternally, from the viewpoint of foam dissipation property free from aslimy feeling during rinsing and a feel after cleansing and subsequentdrying.

As the internal olefin sulfonate composition of the present invention isobtained by sulfonating an internal olefin, followed by neutralizationand hydrolysis as described above, an unreacted raw material internalolefin and inorganic compounds may remain in the composition. It ispreferred that the contents of these components are much smaller.

A content of the raw material internal olefin in the internal olefinsulfonate composition of the present invention is preferably less than5.0% by mass, more preferably less than 3.0% by mass, more preferablyless than 1.5% by mass, more preferably less than 1.0% by mass and evenmore preferably less than 0.05% by mass with respect to the amount ofthe internal olefin sulfonate from the viewpoint of foam dissipationproperty free from a slimy feeling during rinsing and a feel aftercleansing and subsequent drying.

The content of the unreacted internal olefin may be measured by a methoddescribed later in Examples.

A content of the inorganic compounds in the internal olefin sulfonatecomposition of the present invention is preferably less than 7.5% bymass, more preferably less than 5.0% by mass, more preferably less than3.0% by mass, and even more preferably less than 1.0% by mass withrespect to the amount of the internal olefin sulfonate from theviewpoint of foam dissipation property free from a slimy feeling duringrinsing and a feel after cleansing and subsequent drying.

In this context, the inorganic compound includes sulfate and alkaliagent. The content of these inorganic compounds may be measured by apotentiometric titration. Specifically, the content may be measured by amethod described later in Examples.

The internal olefin sulfonate composition of the present invention maycontain a hydroxy form and an olefin form having any number of carbonatoms which are different from that of the component (A) and thecomponent (B). The number of carbon atoms in the hydroxy form and theolefin form other than the component (A) and the component (B) ispreferably from 8 to 24, more preferably from 14 to 20, more preferably14 or 18, and even more preferably 14 from the viewpoint of foamdissipation property free from a slimy feeling during rinsing and a feelafter cleansing and subsequent drying. These hydroxy forms and olefinforms having various numbers of carbon atoms are derived from theinternal olefin used as a raw material.

The internal olefin sulfonate composition of the present invention maycontain other components, for example, water as a medium, a pH adjuster,a viscosity reducing agent, an organic solvent, and polyhydric alcohols,in addition to the components described above.

<Method for Producing Internal Olefin Sulfonate Composition>

The internal olefin sulfonate composition may be produced by sulfonatinga raw material internal olefin composition containing a raw materialinternal olefin having 8 to 24 carbon atoms, followed by neutralizationand hydrolysis. More specifically, for example, the composition may beproduced in accordance with the methods described in U.S. Pat. Nos.1,633,184 and 2,625,150, and Tenside Surf. Det. 31 (5) 299 (1994), andthe like.

As mentioned above, in the present invention, a raw material internalolefin refers to an olefin substantially having a double bond inside theolefin chain. A content of the α-olefin in which a double bond ispresent at a C-1 position in the raw material internal olefin is, in thetotal content of the component (A) and the component (B), preferablyless than 2.8% by mass and more preferably 2.0% by mass or less, fromthe viewpoint of foam dissipation property free from a slimy feelingduring rinsing and a feel after cleansing and subsequent drying. Thecontent of the α-olefin in which a double bond is present at a C-1position in the raw material internal olefin is, in the total content ofthe component (A) and the component (B), preferably 0.01% by mass ormore, more preferably 0.1% by mass or more, and even more preferably0.3% by mass or more, from the viewpoint of cost and productivity.Considering these viewpoints together, the content of the α-olefinsulfonate in which the sulfonate group is positioned at the C-1 positionof an olefin chain or an alkane chain is, in the total content of thecomponent (A) and the component (B), preferably 0.01% by mass or moreand less than 2.8% by mass, more preferably 0.1% by mass or more andless than 2.8% by mass, more preferably 0.3% by mass or more and lessthan 2.8% by mass, and even more preferably 0.3% by mass or more and2.0% by mass or less.

From the viewpoint of foam dissipation property free from a slimyfeeling during rinsing and a feel after cleansing and subsequent dryingof the internal olefin sulfonate composition obtained thus, the numberof carbon atoms in the raw material internal olefin is preferably from 8to 24, more preferably from 12 to 20, more preferably from 12 to 18,more preferably from 12 to 16, and even more preferably 12 and 16. Aninternal olefin to be used as a raw material may be used singly, or acombination of two or more thereof may be used.

When the internal olefin sulfonate composition is obtained bysulfonating the raw material internal olefin composition, followed byneutralization and hydrolysis, the content of the internal olefin inwhich a double bond is present at a C-2 position in the raw materialinternal olefin composition is preferably from 15 to 45% by mass, morepreferably from 15 to 40% by mass, and even more preferably from 15 to35% by mass.

In the synthesis of the internal olefin sulfonate composition, thecontent of the raw material internal olefin in which a double bond ispresent at a C-2 position in the raw material internal olefincomposition may be measured by a gas chromatograph (hereinbelow,abbreviated as GC). Specifically, this content may be measured by themethod described later in Examples.

The raw material internal olefin composition may contain a paraffincomponent. A content of the paraffin component is preferably less than5% by mass, more preferably less than 3% by mass, more preferably 1% bymass or less, and even more preferably 0.1% by mass or less, from theviewpoint of foam dissipation property free from a slimy feeling duringrinsing and a feel after cleansing and subsequent drying.

The content of the paraffin component may be measured by, for example,GC-MS.

The sulfonation reaction may be carried out by reacting a sulfurtrioxide gas with a raw material internal olefin composition at a ratioof from 1 to 1.2 moles of sulfur trioxide per mole of the raw materialinternal olefin. The reactions may be carried out at a reactiontemperature of from 20 to 40° C.

Neutralization is carried out by reacting from 1 to 1.5 times the molaramount of an alkaline aqueous solution such as sodium hydroxide,potassium hydroxide, ammonia or 2-aminoethanol with the theoreticalvalue of sulfonate group.

The hydrolysis reaction may be carried out at from 90 to 200° C. forfrom 30 minutes to three hours in the presence of water. These reactionsmay be successively carried out. Also, upon completion of the reactions,the products may be purified by extraction, washing, or the like.

Also, in the production of the internal olefin sulfonate composition,the raw material internal olefin in which the number of carbon atoms isdistributed in from 8 to 24 may be subjected as a raw material internalolefin composition to sulfonation, neutralization, and hydrolysis toproduce the internal olefin sulfonate composition. Alternatively, theraw material internal olefin having a uniform number of carbon atoms maybe subjected to sulfonation, neutralization, and hydrolysis to produceinternal olefin sulfonic acid, which is then mixed with a plurality ofinternal olefin sulfonates each having different number of carbon atomsto produce the internal olefin sulfonate composition.

The internal olefin sulfonate composition of the present inventionexerts good foamability together with foam dissipation property freefrom a slimy feeling during rinsing and a feel after cleansing andsubsequent drying at high levels, and is thus useful as a cleansingingredient. Specifically, it can be used in household cleansing agentssuch as hair shampoos, body cleansers, laundry detergents, and kitchendetergents, and is particularly useful as a base for the hair shampoo.

<Cleansing Composition>

The cleansing composition of the present invention is not particularlylimited as long as it contains (A) an internal olefin sulfonate having16 carbon atoms and (B) an internal olefin sulfonate having 12 carbonatoms, wherein a content mass ratio of the component (A) to thecomponent (B), (A/B), is from 10/90 to 90/10, as in the internal olefinsulfonate composition of the present invention. The cleansingcomposition of the present invention may contain other componentsdepending on the intended purpose. Examples of the other componentsinclude other surfactant, a foaming increasing agent, and an auxiliaryagent or the like. The total content of (A) the internal olefinsulfonate having 16 carbon atoms and (B) the internal olefin sulfonatehaving 14 carbon atoms in the cleansing composition is preferably from0.1 to 80% by mass, more preferably from 1 to 50% by mass, and even morepreferably from 2 to 30% by mass.

The other surfactant is preferably, for example, an alkyl sulfate or analkyl polyoxyalkylene sulfate. Examples of the auxiliary agent include,but not particularly limited to, water, polymer, an oil solution,silicone, a moisturizing agent, a viscosity regulator, a preservative,an anti-inflammatory agent, an antioxidant, an ultraviolet absorber, asequestering agent, a pearlescent agent, a dye, a fragrance, an enzyme,a bleaching agent, a bleach activator, and a pH adjuster.

The cleansing composition of the present invention may be produced, forexample, by formulating the internal olefin sulfonate compositionobtained as described above, and may be produced by further mixing theinternal olefin sulfonate composition with the components describedabove.

In relation to the embodiments mentioned above, the present inventionfurther discloses the following internal olefin sulfonate compositionand cleansing composition:

<1> An internal olefin sulfonate composition comprising (A) an internalolefin sulfonate having 16 carbon atoms and (B) an internal olefinsulfonate having 12 carbon atoms, wherein a content mass ratio of thecomponent (A) to the component (B), (A/B), is from 10/90 to 90/10.<2> The internal olefin sulfonate composition according to <1>, whereinthe content mass ratio of the component (A) to the component (B), (A/B),in the internal olefin sulfonate composition is preferably from 10/90 to50/50, more preferably from 10/90 to 25/75, and even more preferablyfrom 10/90 to 15/85.<3> The internal olefin sulfonate composition according to <1>, whereinthe content mass ratio of the component (A) to the component (B), (A/B),in the internal olefin sulfonate composition is preferably from 25/75 to75/25, more preferably from 40/60 to 75/25, and even more preferablyfrom 40/60 to 60/40.<4> The internal olefin sulfonate composition according to any one of<1> to <3>, wherein a total content of the component (A) and thecomponent (B) in the internal olefin sulfonate composition is preferably50% by mass or more, more preferably 70% by mass or more, morepreferably 80% by mass or more, more preferably 90% by mass or more,more preferably 95% by mass or more, more preferably 96.5% by mass ormore, and even more preferably 97% by mass or more, with its upper limitbeing preferably 100% by mass.<5> The internal olefin sulfonate composition according to any one of<1> to <4>, wherein a content of the internal olefin sulfonate in whicha sulfonate group is present at a C-2 position in the internal olefinsulfonate having 16 and 12 carbon atoms is preferably 25% by mass orless and more preferably 22% by mass or less, and preferably 5% by massor more and more preferably 7% by mass or more.<6> The internal olefin sulfonate composition according to any one of<1> to <5>, wherein a mass ratio of a content of a hydroxy form to acontent of an olefin form, (hydroxy form/olefin form), in the internalolefin sulfonate having 16 and 12 carbon atoms is preferably from 50/50to 100/0, more preferably from 60/40 to 100/0, more preferably from70/30 to 100/0, more preferably from 75/25 to 100/0, and even morepreferably from 75/25 to 95/5.<7> The internal olefin sulfonate composition according to any one of<1> to <6>, wherein a content of a raw material internal olefin in theinternal olefin sulfonate composition is preferably less than 5.0% bymass, more preferably less than 3.0% by mass, more preferably less than1.5% by mass, more preferably less than 1.0% by mass, and even morepreferably less than 0.05% by mass with respect to the amount of theinternal olefin sulfonate.<8> The internal olefin sulfonate composition according to any one of<1> to <7>, wherein a content of inorganic compound in the internalolefin sulfonate composition is preferably less than 7.5% by mass, morepreferably less than 5.0% by mass, more preferably less than 3.0% bymass, and even more preferably less than 1.0% by mass with respect tothe amount of the internal olefin sulfonate.<9> The internal olefin sulfonate composition according to any one of<1> to <8>, wherein the number of carbon atom in the hydroxy form andthe olefin form other than component (A) and component (B) in theinternal olefin sulfonate composition is preferably from 8 to 24, morepreferably from 14 to 20, more preferably 14 or 18, and even morepreferably 14.<10> The internal olefin sulfonate composition according to any one of<1> to <9>, obtained by sulfonating a raw material internal olefincomposition containing an internal olefin, followed by neutralizationand then hydrolysis, with a content of the internal olefin in which adouble bond is present at a C-2 position being preferably from 15 to 45%by mass.<11> The internal olefin sulfonate composition according to <10>,wherein a content of the internal olefin in which a double bond ispresent at a C-2 position in the raw material internal olefincomposition is from 15 to 40% by mass.<12> A cleansing composition obtained by formulating the internal olefinsulfonate composition according to any one of <1> to <11>.<13> A cleansing composition comprising (A) an internal olefin sulfonatehaving 16 carbon atoms and (B) an internal olefin sulfonate having 12carbon atoms, wherein a content mass ratio of the component (A) to thecomponent (B), (A/B), is from 10/90 to 90/10.<14> The cleansing composition according to <12> or <13>, wherein acontent of the internal olefin sulfonate is preferably from 0.1 to 80%by mass.<15> The cleansing composition according to any one of <12> to <14>,further comprising one or more preferably selected from the groupconsisting of an alkyl sulfate and an alkyl polyoxyalkylene sulfate.<16> A method for washing hair, comprising applying the cleansingcomposition according to any one of <12> to <15> to hair, followed bywashing and then rinsing.<17> A method for washing skin, comprising applying the cleansingcomposition according to any one of <12> to <15> to skin, followed byrinsing.<18> Use of the cleansing composition according to any one of <12> to<15> for washing hair.<19> Use of the cleansing composition according to any one of <12> to<15> for washing skin.

EXAMPLES

Hereinbelow, the present invention will be specifically described withreference to Examples. It should be noted that unless otherwisespecifically noted, the content of each of the components is expressedby % by mass in the following Tables. Also, the methods for measuringvarious physical properties are as follows.

(1) Conditions of Measurement (i) Method for Measuring the Position of aDouble Bond in the Internal Olefin

The position of a double bond in an internal olefin was measured by gaschromatography (hereinbelow, abbreviated as GC). Specifically, aninternal olefin was converted to a dithiated derivative by reaction withdimethyl disulfide, and then each component was separated by GC. Theposition of a double bond in an internal olefin was determined by thepeak area of each component.

The apparatus and analytical conditions used for the measurement are asfollows. GC apparatus “HP6890” (the product of Hewlett-Packard Company);Column “Ultra-Alloy-1HT capillary column” (30 m×250 μm×0.15 μm, theproduct of Frontier Laboratories Ltd.); Detector (hydrogen flameionization detector (FID)); Injection temperature of 300° C.; Detectortemperature of 350° C.; and He flow rate of 4.6 mL/min.

(ii) Method for Measuring the Content of Internal Olefin Sulfonate inwhich a Sulfonate Group is Present at a C-2 Position

The linkage position of the sulfonate group was measured by GC.Specifically, the internal olefin sulfonate was reacted withtrimethylsilyldiazomethane to form a methyl-esterified derivative. Then,each component was separated by GC. Each of a peak area was regarded asa mass ratio, and the content of internal olefin sulfonate in which asulfonate group is present at a C-2 position was quantitated.

The apparatus and analytical conditions used for the measurement are asfollows. GC apparatus “Agilent technology 6850” (the product of AgilentTechnologies, Inc.); Column “HP-1 capillary column” (30 m×320 μm×0.25μm, the product of Agilent Technologies, Inc.); Detector (hydrogen flameionization detector (FID)); Injection temperature of 300° C.; Detectortemperature of 300° C.; He flow rate of 1.0 mL/min.; and Oven (60° C. (0min.)→10° C./min.→300° C. (10 min.)).

(iii) Method for Measuring the Mass Ratio of Hydroxy Form/Olefin Form

The mass ratio of hydroxy form/olefin form was measured by HPLC-MS.Specifically, the hydroxy form and the olefin form were separated byHPLC and each form was identified by separately analyzing with MS. Fromthe resulting GC-MS peak area, the fraction of each form was determined.

The apparatus and analytical conditions used for the measurement are asfollows. HPLC apparatus “Agilent technology 1100” (the product ofAgilent Technologies, Inc.); Column “L-column ODS 4.6×150 mm” (theproduct of Chemicals Evaluation and Research Institute, Japan); Samplepreparation (diluted 1000-fold with methanol); Eluent A (10 mM ammoniumacetate in water); Eluent B (10 mM ammonium acetate in methanol),Gradient (0 min (A/B=30/70%)→10 min (30/70%)→55 min (0/100%)→65 min(0/100%)→66 min (30/70%)→75 min (30/70%)); MS apparatus “Agilenttechnology 1100 MS SL (G1946D)” (the product of Agilent Technologies,Inc.); and MS detection (anion detection m/z 60-1600, UV 240 nm).

(iv) Method for Measuring the Content of the Raw Material InternalOlefin

The content of the raw material internal olefin was measured by GC.Specifically, ethanol and petroleum ether were added to an aqueoussolution of internal olefin sulfonate, followed by extraction to giveolefin in the petroleum ether phase. From the GC peak area of theolefin, the amount thereof was quantitated.

The apparatus and analytical conditions used for the measurement are asfollows. GC apparatus “Agilent technology 6850” (the product of AgilentTechnologies, Inc.); Column “Ultra-Alloy-1HT capillary column, 15 m×250μm×0.15 μm” (the product of Frontier Laboratories, Ltd.); Detector(hydrogen flame ionization detector (FID)); Injection temperature of300° C.; Detector temperature of 350° C.; and He flow rate of 3.8mL/min.

(v) Method for Measuring the Content of Inorganic Compound

The content of inorganic compound was measured by potentiometrictitration and neutralization titration. Specifically, the content ofNa₂SO₄ was quantitated by measuring sulfate ion (SO₄ ²⁻) bypotentiometric titration. Also, the content of NaOH was quantitated byneutralization titration with diluted hydrochloric acid.

(vi) Method for Measuring the Content of the Paraffin Component

The content of the paraffin component was measured by GC. Specifically,ethanol and petroleum ether were added to an aqueous solution ofinternal olefin sulfonate, followed by extraction to give paraffin inthe petroleum ether phase. From the GC peak area of the paraffin, theamount thereof was quantitated.

It should be noted that the apparatus and analytical conditions used arethe same as those used for the measurement of the content of the rawmaterial internal olefin.

(2) Production of an Internal Olefin [Production Example A] Synthesis ofC16 Internal Olefins in which 16.3% by Mass of Double Bonds was Presentat C-2 Position

Into a flask with a stirrer, 7000 g (28.9 moles) of 1-hexadecanol“KALCOL 6098” (the product of Kao Corporation), and as a solid acidcatalyst, 700 g (10% by mass relative to the raw material alcohol) ofγ-alumina (STREM Chemicals, Inc.) were placed, and a reaction wasallowed to proceed for five hours at 280° C. while stirring and passingnitrogen (7000 mL/minute) through the system. The alcohol conversionratio was 100% and the purity of C16 internal olefin was 99.7% after thecompletion of the reaction. The resulting crude internal olefin wastransferred to a distillation flask and distilled at from 136 to 160°C./4.0 mmHg, whereby 100% pure internal olefin having 16 carbon atomswas obtained. The double bond distribution in the resulting internalolefin was 0.7% by mass at C-1 position, 16.3% by mass at C-2 position,15.1% by mass at C-3 position, 15.7% by mass at C-4 position, 17.1% bymass at C-5 position, 14.2% by mass at C-6 position, and 20.8% by massat sum of C-7 and 8 positions.

[Production Example B] Synthesis of C12 Internal Olefins in which 33.1%by Mass of Double Bonds was Present at C-2 Position

Into a flask with a stirrer, 6000 g (26.7 moles) of 1-dodecene“LINEALENE 12” (manufactured by Idemitsu Kosan Co., Ltd.), and as asolid acid catalyst, 180 g (3% by mass relative to the raw materialα-olefin) of protic β-zeolite “CP-814E, Zeolyst International, Inc.”were placed, and the reaction was allowed to proceed for 20 hours at120° C. while stirring. Subsequently, the crude internal olefin wastransferred to a distillation flask and distilled at from 124 to 136°C./7.5 mmHg, whereby 100% pure internal olefin having 12 carbon atomswas obtained. The double bond distribution in the resulting internalolefin was 0.5% by mass at C-1 position, 33.1% by mass at C-2 position,23.7% by mass at C-3 position, 21.2% by mass at C-4 position, 15.0% bymass at C-5 position, and 6.6% by mass at C-6 position.

(3) Production of an Internal Olefin Sulfonate [Production Example 1](Synthesis of C16 Internal Olefin Sulfonate)

Into a thin film sulfonation reactor having an outer jacket, theinternal olefin having 16 carbon atoms (the content of an internalolefin in which a double bond is present at a C-2 position is 16.3% bymass) obtained in Production Example A was placed, and the sulfonationreaction was carried out by using sulfur trioxide gas under conditionsof passing cooling water at 20° C. through the outer jacket of thereactor. The molar ratio of SO₃/internal olefin for the sulfonationreaction was set at 1.09. The resulting sulfonation product was added toan alkaline aqueous solution prepared with 1.5 times the molar amount ofsodium hydroxide relative to the theoretical acid value, followed byneutralization at 30° C. for one hour while stirring. The resultingneutralized product was hydrolyzed by heating at 160° C. for one hour inan autoclave, whereby a crude product of sodium C16 internal olefinsulfonate was obtained. Then, 300 g of the crude product was transferredto a separatory funnel, to which 300 mL of ethanol was added and then300 mL of petroleum ether was added per operation, whereby oil-solubleimpurities were removed by extraction. At this time, inorganic compounds(mainly composed of sodium sulfate) which were precipitated at theoil-water interface by the addition of ethanol were also separated andremoved from the aqueous phase by the oil-water separation operation.The above removal/extraction operation was repeated three times. Then,the aqueous phase side was evaporated to dryness, whereby sodium C16internal olefin sulfonate was obtained. The mass ratio of hydroxy foam(sodium hydroxyalkane sulfonate)/olefin form (sodium olefin sulfonate)in the obtained sodium internal olefin sulfonate was 88/12. Also, thecontent of the raw material internal olefin contained in the obtainedsodium internal olefin sulfonate was less than 100 ppm (below the GCdetection limit), and that of inorganic compounds was 0% by mass. Also,the content of an internal olefin sulfonate in which a sulfonate groupis present at a C-2 position was 9.3% by mass.

[Production Example 2] (Synthesis of C12 Internal Olefin Sulfonate)

A sodium C12 internal olefin sulfonate was obtained under the sameconditions as those used in Production Example 1 from the internalolefin having 12 carbon atoms (the content of an internal olefin inwhich a double bond is present at a C-2 position is 33.1% by mass)obtained in Production Example B.

The mass ratio of hydroxy form/olefin form in the obtained sodiuminternal olefin sulfonate was 92/8. Also, the content of the rawmaterial internal olefin contained in the obtained sodium internalolefin sulfonate was less than 100 ppm (below the GC detection limit)and that of inorganic compounds was 0.2% by mass. Also, the content ofan internal olefin sulfonate in which a sulfonate group is present at aC-2 position was 21.0% by mass.

Production Example 3

The composition obtained in Production Example 1 and the compositionobtained in Production Example 2 were formulated and mixed at a massratio of 10:90 to obtain internal olefin sulfonate composition 1.

Production Example 4

The composition obtained in Production Example 1 and the compositionobtained in Production Example 2 were formulated and mixed at a massratio of 25:75 to obtain internal olefin sulfonate composition 2.

Production Example 5

The composition obtained in Production Example 1 and the compositionobtained in Production Example 2 were formulated and mixed at a massratio of 50:50 to obtain internal olefin sulfonate composition 3.

Production Example 6

The composition obtained in Production Example 1 and the compositionobtained in Production Example 2 were formulated and mixed at a massratio of 75:25 to obtain internal olefin sulfonate composition 4.

Production Example 7

The composition obtained in Production Example 1 and the compositionobtained in Production Example 2 were formulated and mixed at a massratio of 90:10 to obtain internal olefin sulfonate composition 5.

<Hair Evaluation>

A hair bundle (hair of a Japanese person free from treatment such asbleach or hair color; approximately 20 cm, 15 g) was cleansed with aplain shampoo shown in Table 1. Then, after application of a plain rinseshown in Table 2, the hair bundle was rinsed off with tap water toobtain a tress for evaluation.

Each of the internal olefin sulfonate compositions 1 to 5 obtained inProduction Examples 3 to 7 was dissolved in ion-exchange water toprepare an aqueous solution (13% by mass) of the internal olefinsulfonate composition. Using these aqueous solutions, five expertpanelists evaluated their foamability, foaming speed, foam dissipationproperty (free from a slimy feeling during rinsing), and feel aftercleansing and subsequent towel drying in accordance with evaluationcriteria and evaluation methods shown below. Specifically, 1.0 g of eachcleansing composition shown in Table 3 was applied to the tress forevaluation and subjected to lathering, cleansing, and then rinsing. Theresults are shown in Table 3.

Table 3 also shows the evaluation results with reference to alkylpolyoxyethylene sulfate (AES), α-olefin sulfonate (AOS), and secondaryalkyl sulfonate (SAS). The concentrations of these surfactants in thecleansing compositions were adjusted to 13% by mass.

TABLE 1 (Composition of plain shampoo) (Component) (%) Sodiumpolyoxyethylene lauryl ether sulfate 11.3 (42.0% in terms of EMAL E-27C(manufactured by Kao Corp.; 27% by weight of active component)) Coconutoil fatty acid N-methylethanolamide 3.0 (AMINON C-11S (manufactured byKao Corp.)) Citric acid 0.2 Methylparaben 0.3 Purified water BalanceTotal 100.0

(Production of Plain Shampoo)

The components were placed in a beaker, heated to 80° C., and thenmixed. After confirmation of uniform dissolution, the mixture was cooledto obtain a plain shampoo.

TABLE 2 (Composition of plain rinse) (Component) (%) Octadecyloxypropyltrimethyl ammonium chloride 3.0 (6.7% in terms of QUARTAMIN E-80K(manufactured by Kao Corp.; 45% by weight of active component)) Stearylalcohol 6.0 (KALCOL 8098 (manufactured by Kao Corp.)) Methylparaben 0.3Purified water Balance Total 100.0

(Production of Plain Rinse)

Octadecyloxypropyl trimethyl ammonium chloride and stearyl alcohol wereplaced in a beaker (A) and melted by heating to 80° C. Purified waterand methylparaben were placed in another beaker (B) and heated to 80° C.while stirring. After confirmation of uniform dissolution, the mixedsolution in the beaker (A) was added to the beaker (B) while stirring at80° C., and an emulsification was carried out for 30 minutes. Theheating was terminated, and it was cooled to room temperature to obtaina plain rinse.

<Evaluation Criteria and Evaluation Methods>

Foamability

5: Foaming properties were very good4: Foaming properties were good3: Ordinary foamability (equivalent to Reference Comparative Example 3:SAS)2: Foaming properties were poor1: Foaming properties were too poor to cleanse hair

Foaming Speed

5: Lathering was very quick and facilitated cleansing4: Lathering was quick3: Ordinary (equivalent to Reference Comparative Example 2: AOS)2: Lathering was slow1: Lathering was very slow

Foam Dissipation Property (Free from a Slimy Feeling During Rinsing)

5: Foam was very quickly dissipated and easily rinsed without a slimyfeeling4: Foam was quickly dissipated and sliminess was hardly felt3: Ordinary (equivalent to Reference Comparative Example 2: AOS)2: Foam was slowly dissipated and sliminess was felt1: Foam was very slowly dissipated and hardly rinsed with persistentsliminess

Feel after Cleansing and Subsequent Towel Drying

5: Cleansing finish was very refreshing without perceivable residuesfrom the cleansing agent4: Cleansing finish was slightly refreshing3: Ordinary (equivalent to Reference Comparative Example 1: AES)2: Cleansing finish was hardly refreshing with slightly perceivableresidues from the cleansing agent1: Cleansing finish was not refreshing with strongly perceivableresidues from the cleansing agent

<Hand Wash Evaluation>

Each of the internal olefin sulfonate compositions 1 to 5 obtained inProduction Examples 3 to 7 was dissolved in ion-exchange water toprepare an aqueous solution (13% by mass) of the internal olefinsulfonate composition. Using these aqueous solutions, five panelistswashed their hands, and evaluated foamability, foaming speed, foamdissipation property (free from a slimy feeling during rinsing), andfeel after cleansing and subsequent towel drying in accordance with thefollowing evaluation criteria and evaluation method. Specifically, 1.0 gof aqueous solution (13% by mass) prepared by using the internal olefinsulfonate compositions shown in Table 3 was applied to the hands andsubjected to lathering, cleansing, and then rinsing. The results areshown in Table 3.

<Evaluation Criteria>

Foaming Speed

5: Lathering was very quick and facilitated cleansing4: Lathering was quick3: Ordinary (equivalent to Reference Comparative Example 2: AOS)2: Lathering was slow1: Lathering was very slow

Foam Dissipation Property (Free from a Slimy Feeling During Rinsing)

5: Foam was very quickly dissipated and easily rinsed without a slimyfeeling4: Foam was quickly dissipated and sliminess was hardly felt3: Ordinary (equivalent to Reference Comparative Example 1: AES)2: Foam was slowly dissipated and sliminess was felt1: Foam was very slowly dissipated and hardly rinsed with persistentsliminess

Feel after Cleansing and Subsequent Towel Drying

5: Cleansing finish was very refreshing without perceivable residuesfrom the cleansing agent4: Cleansing finish was slightly refreshing3: Ordinary (equivalent to Reference Comparative Example 2: AOS)2: Cleansing finish was hardly refreshing with slightly perceivableresidues from the cleansing agent1: Cleansing finish was not refreshing with strongly perceivableresidues from the cleansing agent

TABLE 3 Reference Comparative Internal olefin sulfonate compositionExamples 1 2 3 4 5 1 2 3 Internal olefin The number of carbon atoms ininternal 16/12 16/12 16/12 16/12 16/12 AES *1 AOS *2 SAS *3 sulfonateolefin sulfonate (mass ratio within (10/90) (25/75) (50/50) (75/25)(90/10) composition parentheses) Total content of C16/12 (%) 100 100 100100 100 Hydroxy form/olefin form 92/8 91/9 90/10 89/11 88/12 Amount ofraw material internal olefin <100 ppm <100 ppm <100 ppm <100 ppm <100ppm relative to amount of C16/12 internal olefin sulfonate Ratio ofsulfonate group present at C-2 19.8 18.1 15.2 12.2 10.5 position inC16/12 internal olefin sulfonate (%) Ratio of double bond present at C-2position 31.4 28.9 24.7 20.5 18.0 in raw material internal olefin (%)Amount of inorganic compound (%) 0.2 0.2 0.1 0.1 0.0 Evaluation HairFoamability 3.8 4.2 4.6 4.4 4.2 2.0 2.4 3.0 results evaluation Foamingspeed 4.0 4.0 4.6 4.0 3.4 2.0 3.0 3.4 Foam dissipation property 5.0 4.84.4 3.8 3.6 2.6 3.0 1.6 during rinsing Feel after cleansing and 4.8 4.23.8 3.4 3.2 3.0 3.4 2.4 subsequent towel drying Hand wash Foaming speed4.6 4.8 4.4 4.0 3.8 2.0 3.0 3.4 evaluation Foam dissipation property 5.04.6 4.2 4.2 4.0 3.0 3.2 2.0 during rinsing Feel after cleansing and 5.04.8 4.6 4.4 4.2 2.6 3.0 1.8 subsequent towel drying *1: Sodium alkylpolyoxyethylene sulfate (AES), manufactured by Kao Corp., EMAL 270S(active component: 70%) *2: Sodium α-olefin sulfonate (AOS),manufactured by Lion Corp., LIPOLAN LB-440 (active component: 36%) *3:Secondary sodium alkyl sulfonate (SAS), manufactured by LANXESS K.K.,Mersolat H95 (active component: 95%)

INDUSTRIAL APPLICABILITY

The internal olefin sulfonate composition of the present invention canexert good foamability together with foam dissipation property free froma slimy feeling during rinsing and a feel after cleansing and subsequentdrying at high levels. Thus, the internal olefin sulfonate compositionof the present invention can be used suitably in the fields of householdcleansing agents such as hair shampoos, body cleansers, laundrydetergents, kitchen detergents, and residential detergents, and is alsosuitable for cosmetic emulsifiers, industrial emulsifiers, industrialcleansing agents or the like.

1. An internal olefin sulfonate composition comprising (A) an internalolefin sulfonate having 16 carbon atoms and (B) an internal olefinsulfonate having 12 carbon atoms, wherein a content mass ratio of thecomponent (A) to the component (B), (A/B), is from 10/90 to 90/10, andwherein a content of the internal olefin sulfonate in which a sulfonategroup is present at a C-2 position in the internal olefin sulfonatehaving 16 and 12 carbon atoms is 25% by mass or less.
 2. The internalolefin sulfonate composition according to claim 1, wherein a totalcontent of (A) the internal olefin sulfonate having 16 carbon atoms and(B) the internal olefin sulfonate having 12 carbon atoms in the internalolefin sulfonate composition is from 50 to 100% by mass.
 3. The internalolefin sulfonate composition according to claim 1, wherein a mass ratioof a content of a hydroxy form in the internal olefin sulfonate having16 and 12 carbon atoms to a content of an olefin form in the internalolefin sulfonate having 16 and 12 carbon atoms, (hydroxy form/olefinform), is from 50/50 to 100/0.
 4. The internal olefin sulfonatecomposition according to claim 1, wherein a content of a raw materialinternal olefin in the internal olefin sulfonate composition is lessthan 5.0% by mass with respect to the amount of the internal olefinsulfonate.
 5. The internal olefin sulfonate composition according toclaim 1, wherein a content of an inorganic compound in the internalolefin sulfonate composition is less than 7.5% by mass with respect tothe amount of the internal olefin sulfonate.
 6. The internal olefinsulfonate composition according to claim 1, obtained by sulfonating araw material internal olefin composition containing a raw materialinternal olefin, followed by neutralization and then hydrolysis, with acontent of the raw material internal olefin in which a double bond ispresent at a C-2 position being from 15 to 45% by mass.
 7. The internalolefin sulfonate composition according to claim 1, wherein a content ofthe raw material internal olefin in which a double bond is present at aC-2 position in the raw material internal olefin composition is from 15to 35% by mass.
 8. The internal olefin sulfonate composition accordingto claim 1, wherein a content mass ratio of the component (A) to thecomponent (B), (A/B), in the internal olefin sulfonate composition isfrom 10/90 to 15/85.
 9. The internal olefin sulfonate compositionaccording to claim 1, wherein a content mass ratio of the component (A)to the component (B), (A/B), in the internal olefin sulfonatecomposition is from 40/60 to 60/40.
 10. A cleansing composition obtainedby formulating the internal olefin sulfonate composition according toclaim
 1. 11. A cleansing composition comprising (A) an internal olefinsulfonate having 16 carbon atoms and (B) an internal olefin sulfonatehaving 12 carbon atoms, wherein a content mass ratio of the component(A) to the component (B), (A/B), is from 10/90 to 90/10.
 12. Thecleansing composition according to claim 11, wherein a total content of(A) the internal olefin sulfonate having 16 carbon atoms and (B) theinternal olefin sulfonate having 12 carbon atoms is from 0.1 to 80% bymass.
 13. The cleansing composition according to claim 11, comprisingone or more selected from the group consisting of an alkyl sulfate andan alkyl polyoxyalkylene sulfate.
 14. The cleansing compositionaccording to claim 11 for dishwashing.
 15. The cleansing compositionaccording to claim 11 for laundry detergent.
 16. The cleansingcomposition according to claim 11 for washing hair.
 17. The cleansingcomposition according to claim 11 for washing skin.